Lubricating composition for machining operations



positions for mach Patented Oct. 11, 1932 UNITED STATES PATENT OFFICE PHILIP E EARTH, OF ST. LOUIS, MISSOURI, ASSIGNOB TO NATIONAL PIGMENTS &

CHEMIC COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI LUBRICATING COMPOSITION FOR MACHINING OPERATIONS Io Drawing.

This invention relates to lubricating comining operations. In machining operations, such as broaching, cutting and tapping, it is the practice to employ a lubricating composition in order to lubricate the machining elements such as cutters, taps, etc., and to keep them cool. Where, however, such a composition has a suspensoid base the tendency is for this base to settle out of the liquid in which the base is suspended. I

One of the objects of this invention, therefore, is to provide a lubricating composition of the character described in which there is combined with the suspensoid base a suspending agent which serves to hold this base in suspension.

Further objects will appear from the detail description in which will be described an illustrated embodiment of this invention.

It is to be understood, however, that this invention is susceptible of various embodiments within the scope of the appended claims.

In accordance with this invention the composition employs a suspensoid base having lubricating properties and there is mixed therewith or added thereto, a suspending agent, which serves to hold the suspensoid in suspension. An agent particularly suitable for this purpose is a concentrated colloidal clay. A suspensoid base particularly suitable, especially in connection with colloidal clay, is barium sulphate.

As an illustrated embodiment of this invention, the composition comprises-80% barium sulphate of a fineness so as to pass through 400 mesh and 20% of a concentrated colloidal clay, a typical sample of which has the following analysis Silica 62 43 Alumina 24.64 Iron oxide 3.20 Calcium carbonate 0.41 agnesium carbonate 2.30 Potassium carbonate 0.15 {Sodium carbonate 0.60 Loss on ignition 6.12

Application filed April 29, 1929. Serial No. 359,177.

The physical analysis of such a sample is as follows:

The barium sulphate and the colloidal clay are mixed dry and can be retained as a dry mixture until ready for use. They can, however, be made into a paste by adding 20% of water and thoroughly mixing the same.

hen it is desired to use it for machining operations, the paste has added thereto about 100% of water. The barium sulphate not only acts as a lubricant, but also absorbs heat and, therefore, tends to keep the cutting elements as well as the work cool. The colloidal clay not only acts as a lubricant and as a soap, but performs the important function of keeping the barium sulphate in suspension.

While the composition embodying this invention is particularly applicable as a lubricating composition for machine operations, it will be understood that it is applicable to other uses in this art. It will, furthermore, be understood that certain features are of utility and may be employed without reference to other features; that is contemplated by and is within the scope of the appended claims. It will, furthermore, be understood that various changes may be made in the proportions and ingredients of the composition within the scope of the appended claims without departing from the spirit of this invention. It is, therefore, to be understood that this invention is not to be limited to the specific details described.

Having thus described the invention, what is claimed is:

1. A lubricating composition base for machining operations, consisting of 80 barium sulphate and 20% colloidal clay.

2. A lubricating composition for machining operations consisting of an aqueous suspension of barium sulphate and concentrated colloidal clay.

3. A lubricating paste composition for machining operations consisting of finely divided barium sulphate as a heat absorbing material, and concentrated colloidal clay of the character described as a soapy suspending agent.

In testimony whereof I aflix my signature this 5th day of April, 1929.

PHILIP E. HARTH. 

